KR100820581B1 - Floating media which is more enhanced in the functions of attachment and filtration than traditional floationg media - Google Patents

Abstract

Floating filter media are provided to improve the efficiency in treatment of suspended solids, organic materials, and nutrient salts, which are contained in wastewater, by mixing activated carbon and sand when the floating filter media are foamed, so as to increase surface areas and densities of the floating filter media. Floating filter media fill a bio-filter system to filter off wastewater. Large-sized filter media(3) have relatively greater densities than small-sized filter media. The large-sized filter media are positioned below the small-sized filter media due to density difference even after backwashing in the bio-filter system so that waste inputted in an upflow type is efficiently filtered off. The large-sized filter media have particle sizes of 5-7 mm, and densities of 0.060-0.090 g/cm^3. The large-sized filter media are prepared by preparing resin beads, mixing 3-4 wt% of volatile foaming agent, 30-80 wt% of water, 0.1-1 wt% of dispersing agent into 16.9-65 wt% of resin beads, agitating the mixed matter in an internal pressure container, heating the stirred matter at a temperature of 147-156°C and a pressure of 1.3-3.5 kgf/cm^2, and foaming the heated matter while discharging the heated matter. The resin beads are prepared by melting and mixing 1-2.5 wt% of powder type activated carbon(31) and 0.5-1.5 wt% of sand particles into 96-98.5 wt% of polypropylene resin.

Description

FLOATING MEDIA WHICH IS MORE ENHANCED IN THE FUNCTIONS OF ATTACHMENT AND FILTRATION THAN TRADITIONAL FLOATIONG MEDIA}

1 is a scanning electron microscope (SEM) photograph of an enlarged surface of a conventional flotation media.

Figure 2 is a perspective view briefly showing a large particle size filter medium with added activated carbon and sand according to the present invention foamed.

Figure 3 is a front view showing a biological filtration system filled with a large particle size filter and a small particle filter material according to the present invention.

Explanation of symbols on the main parts of the drawings

1: Biological filtration system 2: Small particle filler

3: large particle size filter material 31: activated carbon

The present invention relates to a flocculation filter with improved adhesion and filtration function of microorganisms and contaminants, and more particularly, to increase the surface area and density by foaming by adding activated carbon and sand particles in the manufacture of flotation filter, to increase the adhesion of microorganisms To promote biological reactions such as organic matter decomposition, nitrification and phosphorus absorption, and to prevent microorganisms from detaching at low loads of wastewater, and to increase the particle size with increased surface area and density in upflow biofiltration systems. It relates to a floating filter with improved adhesion and filtering ability to increase the filtering efficiency by placing the floating filter in the lower portion of the floating filter having a small particle diameter.

Generally, biological filtration system using flotation filter fills the flotation filter to the biofiltration system at an appropriate ratio, attaches microorganisms to the flotation filter, and treats organic matter, nitrogen and phosphorus by biological mechanism, or inflow and outflow of wastewater. Is treating some of the solids by filtration.

Sewage / wastewater treatment technology using floating media can increase the amount of microorganisms in the reactor by inducing the growth of microorganisms, and thus, it is possible to treat high-load wastewater in a short time and even if toxic substances are introduced from outside It is less affected by the cold weather, and also has the advantage of being able to be treated appropriately under the influence of the temperature in winter in Korea.

However, in spite of these advantages, the method of simply filling the floating filter in the biofiltration system cannot bring about the maximization of the treatment efficiency using the filtration and biological treatment mechanism due to the fundamental problem of the conventional floating filter.

The first problem with existing flotation media is that the surface area of flotation media is smaller than that used for other biological treatments. In the case of media used for biological treatment, the voids are connected to the inside of the media and have a relatively high specific surface area, but in the case of floating media, only the surface is ruggedly formed so that the specific surface area is relatively lower than other media. .

1 is an enlarged SEM image of the surface of the existing flotation media, it can be seen that the surface of the flotation media is simply uneven, so that there is a limit in providing a surface area to which microorganisms can be attached.

As such, when the surface area of the flotation filter is small, there are few microorganisms attached to the flotation filter, and when the contaminants enter the low load, the microorganisms are easily detached and the treatment efficiency of the biofiltration system decreases.

The second problem of the existing flocculation media is that when the flocculation media is arranged after the backwashing process of the biological filtration system, the flotation media with the larger particle size are located in the upper part because the density is smaller, and the flocculation media with the smaller particle size have a higher density. Due to its size, it is located at the bottom, so that the gap between the upper floating media becomes large, and the gap between the lower floating media becomes small.

When this happens, most of the solids are quickly detained at the bottom of the biofiltration system and the time to reach the breakthrough point is introduced when the wastewater is introduced into the upflow, which is widely used in biofiltration systems. It is short and the filtration efficiency falls.

As a result, the above-mentioned problems of the flotation media have resulted in deterioration of the biological and physical sewage treatment efficiency of the biofiltration system.

In the present invention, in order to solve the problem of the conventional flotation filter, by increasing the surface area and density of the flotation filter by increasing the surface area and density of the flotation filter by mixing the coating material such as activated carbon and sand during foaming of the flotation filter, after the backwash When rearranging, the large grain size filter is placed at the bottom and the small grain size filter is placed at the top to increase the treatment efficiency of suspended solids, organic matter and nutrients (nitrogen and phosphorus) contained in sewage and wastewater. The purpose of the present invention is to provide a floating media with improved adhesion and filtration.

In order to achieve the above object, the present invention is to increase the density when the particle size is large, the density is small when the particle size is small in the biofiltration system filled in the biofiltration system to filter the waste water After backwashing, the main difference is that the flocculation media with large particle size is located under the flocculation media with small particle diameter, so that the flocculation media with improved adhesion and filtration function can efficiently filter the wastewater flowing upflow. It is set as a configuration.

The particle diameter may be considered large and small through relative comparison.

However, when considering the particle size for a more clear description is as follows.

In the case of floating media with a particle diameter of 5 to 7 mm (hereafter referred to as large particle size media), the density should be 0.060 to 0.090 g / cm3. In case of floating media with a particle size of 2 to 4 mm (hereinafter referred to as small particle size media), the density should be between 045 and 0.060 g / cm ³ and the absorption rate is 0.32 g / 100 cm ³ . Use to ensure that large particle size filters can be placed underneath the small particle size filter due to density differences even after backwashing in the biofiltration system.

As such, the reason why the large particle bonus material should be positioned below the small particle bonus after backwash will be described later.

In addition, in order to improve the adhesion of microorganisms and contaminants of the flotation media according to the present invention is achieved by adding foamed activated carbon and sand particles during the production of flotation media.

Hereinafter, the technical configuration will be described in detail with reference to the accompanying drawings.

First, the present invention is to improve the adhesion of microorganisms and contaminants in the biofiltration system as compared to the conventional flotation filter, and to arrange the filtration of wastewater after the back-washing required in the operation of the biofiltration system effectively As to the floating media to improve the pollutant filtering mechanism,

1 is a scanning electron microscope (SEM) photograph of an enlarged surface of a conventional general injury filter material. Looking at the photograph, a few voids are formed only on the surface of the conventional injury filter material so that the surface area thereof is very low. You can see that. As such, when the surface area is low, the amount of microbial adhesion is significantly reduced, thereby decreasing the water treatment efficiency.

Figure 2 shows a large particle diameter filter material (3) foamed by mixing the activated carbon and sand according to the present invention, compared to the conventionally used flotation media by foaming by adding the activated carbon 31 and the sand as a coating material having a large surface area A large particle size filler having a large surface area can be obtained.

In this way, by adding activated carbon 31 to the large particle filler 3, the large particle filler 3 can increase the surface area, and the large surface area facilitates the attachment of microorganisms, thereby increasing the amount of adherent microorganisms. . And the increased adhesion of the microorganisms increases the water treatment efficiency, even if the influent wastewater flows to a low load it is possible to prevent the desorption phenomenon of the adherent microorganisms.

In order to increase the filtration efficiency in the biofiltration system (1), in addition to increasing the surface area of the flotation filter as described above, the large particle injury filter (3) for the flotation filter rearranged after backwashing in the biofiltration system (1) Is achieved by positioning the lower particle size bonus material 2 below.

In general, however, the larger the particle size, the larger the particle size is, the more air is injected into the foam and the density is lowered. As a result, the small particle flotation filter material (2) is the biofiltration system after backwashing in the biofiltration system. It is located in the lower part of (1), the large particle size filter (3) is located in the upper portion of the biofiltration system (1).

As described above, when the large-sized particulate filter (3) is located at the top and the small-sized particulate filter (2) is located at the bottom after the backwashing in the biological filtration system (1), it is frequently used in the biofiltration system (1) process. When the wastewater flows into the stream, most of the solids are quickly detained under the biofiltration system, and the adsorption layer adsorbed on the biofilm of the flotation media reaches its peak and no further adsorption occurs. The time to reach the breakthrough point (breakthrough time) is very short and the filtration efficiency is very low.

Therefore, the arrangement of the flotation filter after backwashing in the biofiltration system is a very important problem. In consideration of such arrangement, the larger the particle diameter, the greater the surface area and the greater the density in preparing the flotation filter.

As described above, the large particle size filter which increases the surface area of the floating filter material and at the same time increases the density is achieved by adding activated carbon and sand particles in the manufacturing of the floating filter material. same.

First, the resin may be used by selecting one kind of polyolefin resin, but for the convenience of description, the present invention will be limited to the polypropylene resin.

Resin beads were prepared by melting and mixing 1 to 2.5% by weight of activated carbon in powder form of 50 to 250 μm with 0.5 to 1.5% by weight of sand particles having 50 to 100 μm to 96 to 98.5% by weight of polypropylene resin. 16.9 ~ 65% by weight of the blowing agent 3 ~ 4% by weight, water 30 ~ 80% by weight, dispersant 0.1 ~ 1% by weight in a pressure vessel and stirred under pressure of 1.3 ~ 3.5kgf / cm ² to 147 ~ 156 ℃ It is prepared by heating and foaming while discharging to the atmosphere through the nozzle.

As described above, when activated carbon and sand particles are added at a predetermined ratio during the manufacture of flotation media, the flotation media not only widens the surface area, but also increases the density by including the activated carbon and the sand particles.

The polypropylene resin is used to cut to a size of 1 ~ 1.5mm in diameter in consideration of the size of the final foam.

Hereinafter, the details of the preparation of the large-diameter filler material will be described in more detail through examples.

Example 1

Resin beads are prepared by melting and mixing 18.5 g of activated carbon powder having a particle diameter of 80 µm and 0.5 g of sand particles having a diameter of 100 µm to 98.5 g of polypropylene resin.

Next, 3 g of pentane, 31.9 ml of water, and 0.1 g of alkylbenzenesulfonic acid soda were mixed with 65 g of the resin beads thus prepared, and stirred at 170 rpm for 10 minutes in a pressure vessel, followed by heating to 147 ° C. under a pressure of 3.5 kgf / cm ² . The foaming is then performed while discharging to the atmosphere through the nozzle.

Example 2

Resin beads are prepared by melting and mixing 2.5 g of activated carbon powder having a particle size of 50 μm and 1.5 g of sand particles having a particle size of 100 μm to 96 g of polypropylene resin.

Next, 4 g of pentane, 35 ml of water, and 1 g of sodium dodecylbenzenesulfonate were mixed with 60 g of the resin beads thus prepared, and stirred at 150 rpm in a pressure-resistant container for 15 minutes, and then heated to 150 ° C. under a pressure of 3.0 kgf / cm ² . After that, it is foamed while discharged to the atmosphere through the nozzle.

Activated carbon added in the preparation of the resin beads is used in 1 to 2.5% by weight relative to the total weight of the resin beads, when less than 1% by weight is not a large surface area for microbial adhesion is attached to microorganisms and contaminants When the capacity is exceeded by 2.5% by weight, a problem arises that the filtration capacity decreases, and when used in excess of 2.5% by weight, due to the increase in volume due to foaming, the particle size is relatively lower than that of the floating particle having a small particle diameter, so that the upper portion of the floating particle having a small particle diameter after backwashing Since there is a problem to be located in the flotation material manufacturing activated carbon is preferably used in the range of 1 to 2.5% by weight based on the total weight.

Sand particles added in the preparation of the resin beads are used in the form of a powder having a particle size of 50 ~ 100㎛ 0.5 to 1.5% by weight relative to the total weight of the resin beads, added in less than 0.5% by weight, or 1.5% by weight When added in excess, since the function as a coating material is inferior, it is preferable to use in the range of 0.5 to 1.5% by weight.

The blowing agent uses any one selected from pentane, chlorofluorocarbons (CFC) or butane, and the dispersing agent uses sodium alkylbenzenesulfonate or sodium dodecylbenzenesulfonate.

FIG. 3 shows the inside of the biofiltration system 1 filled with the large particle size filter material 3 mixed with activated carbon and sand, and the particle size of the large particle material filter 3 is small due to the difference in density even after backwashing. It shows the internal structure of the biological filtration system to be located under the particle size filter (2).

As such, the large particle size filter medium (3) has a high density and is located under the biological filtration system (1) to form large voids between the floating filter materials and the small particle size filter material (2) having a small particle size in which activated carbon is not mixed. Because of its relatively small density, it is located on the upper part of the large particle diameter filter medium having a large particle size, thereby forming small voids between the floating media having a small particle size. As a result, the filtration efficiency in the upflow biofiltration system can be maximized by the arrangement of the flotation media.

As described above, the flotation filter according to the present invention increases the surface area by mixing and foaming activated carbon and sand particles upon foaming the flotation filter, thereby placing the flotation filter having the increased surface area under the upflow biofiltration system. By placing the floating media without mixed activated carbon on the upper side of the upflow filtration system, the problem caused by the rearrangement of the floating media by backwash can be solved.

Increased adhesion ability of microorganisms and contaminants to promote biological reactions such as organic decomposition, nitrification and phosphorus absorption, and prevent filtration of microorganisms at low load inflow of wastewater, maximizing filtration efficiency compared to existing biofiltration systems It can be done.

In addition, by increasing the surface area of the flotation media, the adhesion amount of microorganisms is increased to increase the treatment efficiency of organic matter and nutrients, and even when the influent wastewater is introduced at a low load, it is possible to prevent microorganism detachment.

Claims (3)

As a flotation filter which fills a biological filtration system and filters wastewater, the flotation filter has a larger particle size filter (3) and a greater density than a small particle filter material (2). Even after backwashing in the biofiltration system (1), the large particle size filter material (3) is located under the small particle filter material (2) due to the difference in density, and the wastewater flowing in the upflow type is discharged. In what can be efficiently filtered, The large particle size filler having a particle diameter of 5 to 7 mm and a density of 0.060 to 0.090 g / cm 3, Resin beads were prepared by melting and mixing 1 to 2.5% by weight of activated carbon in powder form of 50 to 250 μm with 0.5 to 1.5% by weight of sand particles having 50 to 100 μm to 96 to 98.5% by weight of polypropylene resin. 16.9 ~ 65% by weight of volatile blowing agent 3 ~ 4% by weight, water 30 ~ 80% by weight, dispersant 0.1 ~ 1% by weight in a pressure vessel and stirred under pressure of 1.3 ~ 3.5kgf / cm ² 147 ~ 156 ℃ Floating media with improved adhesion and filtration, characterized in that the foam is produced by heating and then blowing into the atmosphere through the nozzle. delete The small particle size filler having a particle size of 2 to 4 mm, a density of 0.045 to 0.060 g / cm ³ , and a water absorption of 0.32 g / 100 cm ³ . Floating media with improved adhesion and filtration.

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